NZ619101B2 - Veterinary Injectable Formulations - Google Patents

Abstract

Disclosed herein are injectable veterinary suspension formulations comprising the antibiotic penethamate (also known as 2-(diethylamino)ethyl (2S,5R,6R)-3,3-dimethyl-7-oxo-6-[(2-phenylacetyl)amino]-4-thia-1-azabicyclo[3.2.0] heptane-2-carboxylate and penethacillin) or a salt thereof and a substantially water free carrier comprising diethylene glycol monoethyl ether (DGMEE) and/or solketal ((2,2-dimethyl-1,3-dioxolan-4-yl)methanol). Such formulations are intended for use in the treatment of mastitis in cattle. lly water free carrier comprising diethylene glycol monoethyl ether (DGMEE) and/or solketal ((2,2-dimethyl-1,3-dioxolan-4-yl)methanol). Such formulations are intended for use in the treatment of mastitis in cattle.

Description

s Form # 5 NEW ZEALAND Patents Act 1953 COMPLETE SPECIFICATION AFTER PROVISIONAL #: DATED: TITLE: Veterinary Injectable Formulations We, ALLEVA ANIMAL HEALTH LIMITED Address: 15 Calman Place, Birkenhead, Auckland, New Zealand, 0626 Nationality:New Zealand do hereby declare the invention for which we pray that a patent may be d to us and the method by which it is to be performed, to be particularly described in and by the following statement: C:\Users\JPIPER\Documents\Complete Specifications.docx Veterinary Injectable Formulations Field This invention relates to antibiotics and in particular to injectable formulations suitable for treating ing dairy .

Background There are a wide variety of bacterial ions, which may infect domestic livestock. Of ular importance are those infections known to cause mastitis in lactating dairy cattle. To combat these infections farmers may treat with an antibiotic indicated for the particular infective organism.

Various antibiotics can be used for this purpose with beta-lactam antibiotics being particularly preferred.

Beta-lactam antibiotics include penicillin derivatives (penams), cephalosporins (cephems), monobactams, and carbapenems.

Penethamate hydriodide [CAS no. 8089] (IUPAC Name: 2-(diethylamino)ethyl (2S,5R,6R)-3, 3- dimethyloxo[(2-phenylacetyl)amino]thiaazabicyclo[3.2.0] ecarboxylate), is an ester of benzyl penicillin. Each gram is lent to 1 million international units (i.u.) of benzyl penicillin (penicillin G).

First recognised in 1948 and developed commercially in the 1950’s (GB759603 patent - “Method for the production of esters of penicillin”, 1956; Jensen, K. A., Dragsted, P. J., Kaier, E. J. and Fredericksen, E.: “Leocillin (Benzyl Penlcillin-Diethylaminoethylester Hydriodide),“ Acta Path. et iol.Scand., 28:407, 1951). It is particularly red for the treatment of gram positive mastitis, respiratory infections, footrot and sub-acute mastitis. 205366NZC_COMPLETESPEC2_20131217_1337_JWP FEE CODE – 1050 The advantageous properties of amate hydriodide are that it is lipophilic salt of a weak base and upon injection, a high proportion will be present in the plasma and tissue in a ised form. Because of this special property penethamate hydriodide has a special ability to diffuse through cell membranes, endothelia and tissue rs, to the site of infection, where it is hydrolysed to the active benzyl penicillin. The levels of penicillin in the milk following injection of penethamate hydriodide are about 10 times higher than the levels following ion of other benzyl–penicillin preparations at an equivalent dose.

These properties mean this product is especially suitable for systemic treatment of acute and subacute mastitis.

While Penethamate hydriodide is a drug of choice in combating bacterial infections in livestock it is not an easy t for the veterinarian or farmer to administer. Because it is not stable when mixed with water, it is provided in a vial containing 5 or 10 grams of penethamate hydriodide as an off white sterile powder for reconstitution.

Dosage of the product is typically 10-15mg/kg body weight daily, with the dose repeated for 1 to 5 days depending on the ion being treated. The dose is injected subcutaneously or uscularly. A 10mg dose of penethamate hydriodide powder would be administered by suspending in 30mL of water. This would result in a suspension containing 333mg/mL or 33.3% w/v. 205366NZC_COMPLETESPEC2_20131217_1337_JWP FEE CODE – 1050 [Link] http://www.mamyzin.com In New Zealand the meat withholding period for animals treated with penethamate dide is 7 days, while milk from d cattle must be discarded for not less than 48 hours after the last treatment of a 5g daily dose and 60 hours after the last treatment of a 10g treatment followed by two daily doses of a 5g treatment.

Commercial examples of Penethamate Hydriodide Injection include: INGEL-MAMYZIN® powder + solvent for injection, MAMYZIN® P powder + solvent for injection, MAMYZIN® Parenteral powder + solvent for injection, MAMYZIN® 5 powder + solvent for ion, MAMYZIN® 10 powder + solvent for injection, MAMYZIN® Vet. powder + solvent for injection, PENETAVET® powder + solvent for injection (all Boehringer Ingelheim, see www.mamyzin.com); PENETHAJECT® (Bayer Bomac); MASTIVET™ PARENTERAL (Divasa ic); YODIMASPEN™(Laboratorios Calier).

To use any of these products the farmer or veterinarian must follow this procedure: 1. Insert the needle of a syringe h the stopper of the water for injection vial 2. Use the e to withdraw the water 3. Pick up the vial containing the penethamate hydriodide powder 4. Insert the syringe needle through the r of the vial . Express the water from the syringe into the vial 6. Withdraw the e from the vial 7. Shake the vial vigorously to disperse the powder through the water 8. Reinsert the syringe needle through the stopper of the vial 9. Withdraw the required dose of the now mixed penethamate hydriodide suspension from the vial . Treat the animal 205366NZC_COMPLETESPEC2_20131217_1337_JWP FEE CODE – 1050 As will be appreciated this is a time consuming task. It is also a task that es the user to be very adept at using the syringe to transfer the water for ion. The fact that it must be mixed before use, often in an on-farm environment, means that there are also increased opportunities to mix the powder incorrectly.

There is therefore a significant need for a simple ready to use formulation of penethamate hydriodide. By this term “ready to use” we mean that no other additives or reconstitution steps are needed – just that it can be shaken or agitated before being stered. Over the years, various attempts have been made to deliver an ed penethamate formulation; including formulations that are ready for injection rather than rely on reconstitution. Surprisingly, and despite the fact that penethamate has been available for almost 60 years none of these ts have met with any degree of success.

Object of the Invention It is an object of the invention to provide veterinary injectable formulations that ameliorate some of the disadvantages and tions of the known art or at least provide the public with a useful choice.

Summary of the ion In a first aspect the invention provides an able veterinary suspension formulation comprising penethamate or a salt thereof and a substantially water free carrier consisting predominately of a biocompatible oil or organic solvent or a combination thereof.

Preferably this is a ready to use suspension formulation of penethamate consisting of penethamate hydriodide in a biocompatible oil or an organic solvent (or a ation thereof), and one or more pharmaceutically acceptable excipients suitable for intramuscular injection in domestic animals; in particular cattle.

Preferably the biocompatible oil is a vegetable oil. 205366NZC_COMPLETESPEC2_20131217_1337_JWP FEE CODE – 1050 The improvement over the prior art relates to the fact that the ation is ready to use without additional preparation, aside from shaking to achieve adequate resuspension. Thus, the formulation can be supplied in a sealed container such as a vial allowing it to be easily shaken before use.

A pharmaceutical suspension is a coarse dispersion in which an internal phase is dispersed uniformly throughout an external phase. The internal phase consists of insoluble solid particles having a specific range of size which is maintained uniformly throughout the external phase with the aid of a single or ation of suspending agents.

The ation of the penethamate ready to use suspension is based on use of a biocompatible oil or organic solvent as the external phase.

In a second aspect the ion provides a ready to use suspension formulation of penethamate or a salt thereof and a ntially water free carrier consisting predominately of a biocompatible oil or an organic solvent (or a combination f).

Preferably the formulation is suitable for intramuscular injection in domestic animals; and in particular cattle.

Preferably the biocompatible oil is selected from the group comprising: canola oil, coconut oil, corn oil, cottonseed oil, olive oil, peanut oil, palm oil, sesame oil, soybean oil, safflower oil, sunflower oil, cerides (which are long chain fatty acid esters of (a) glycerol or (b) trihydroxy, dihydroxy, monohydroxy or even polyhydroxy compounds), and mixtures of cerides and fatty acids (such as MIGLYOL®, Cremer).

Preferably the organic solvent is selected from the group comprising: diethylene glycol hyl ether (abbreviated to DGMEE), Solketal (IUPAC name: (2,2-Dimethyl-1,3-dioxolanyl)methanol), and Propylene Glycol.

Preferably the formulation contains a surfactant Preferably, the surfactant is ed from sorbitan esters, polyoxyethylated sorbitan , polyethylene glycol stearate and lecithin 205366NZC_COMPLETESPEC2_20131217_1337_JWP FEE CODE – 1050 Preferably the injectable ation also includes a moisture scavenger.

Preferably the formulation is provided in ready to use vials.

Optionally the formulation may include other actives. Preferably they are soluble in the carrier.

More ably the other actives include analgesics. ably the analgesic is selected from flunixin, tolfenamic acid, carprofen, meloxicam, metamizole and ketoprofen (IUPAC name: (RS)—2—(3~benzoylpheny|) propanoic acid).

Preferably the analgesic is ketoprofen.

Brief Description: The invention will now be described by way of non-limiting e. ption of the Preferred ment(s): The following description will describe the invention in relation to preferred embodiments of invention, namely veterinary injectable formulations.

The invention is in no way limited to these preferred embodiments as they are purely to exemplify the invention only and that possible variations and cations would be readily apparent without departing from the scope of the invention.

The tuents listed in Table l are preferred in the invention: Table l: Constituents preferred in Penethamate Hydriodide Suspension Constituent Purpose Preferred Concentration (W/V) 205366NZC_COMPLETESPEC2_20131217_1337_JWP FEE CODE — 1050 Penethamate hydriodide Active ingredient 10-70% Oleaginous or Organic Carrier for the penethamate 20-90% solvent vehicle/s hydriodide particles Miscible c vehicle/s Carrier for the penethamate 0-20% hydriodide particles Surfactant/s Lower the surface n of 0-20% the liquid once injected Buffer/s Stabilize the suspension to a 0-5% desired pH range Suspending agent/s Form film around particle 0-10% and decrease interparticle attraction thereby imparting viscosity to the solution.

Wetting agent/s Help disperse solids in the 0-10% continuous liquid phase Flocculating agent/s Flocculate the amate 0-10% drug les Thickener/s Increase the viscosity of 0-5% suspension Surface modifier/s Adsorbed onto surface of 0-5% active ingredient to help prevent particle agglomeration Moisture scavenger/s Absorb any al water 0-5% Osmotic agents Adjust osmotic pressure 0-5% comparable to biological fluid Local hetic/s Reduce any pain associated 0-5% with injection Preservative/s Prevent microbial growth 0-5% 205366NZC_COMPLETESPEC2_20131217_1337_JWP FEE CODE – 1050 Antioxidant/s Inhibit the oxidation of 0-1% penethamate hydriodide in the formulation It is also preferred that water will essentially be absent from the formulation.

The invention demonstrates that a significantly more stable ation is achieved when penethamate hydriodide is formulated as a liquid suspension in which water is essentially absent.

Because of the nt water solubility of penethamate it has also proven possible to formulate a liquid sion in which there is l difference between the pharmacokinetics of the ng marketed aqueous reconstitutable suspensions (such as MAMYZIN®, nger Ingelheim; PENETHAJECT®, Bayer Bomac) and the ready to use suspension which is the subject of this invention.

Surprisingly the s conducted in the development of the invention have also demonstrated that it is possible to include penethamate hydriodide in a ready to use suspension at a level at least as concentrated as the 333mg/ml concentration of the existing marketed aqueous reconstitutable suspension in its mixed condition.

Even more surprisingly it has been proven possible to formulate a suspension of penethamate dide in which only organic solvents are used as the vehicle.

The composition preferably includes penethamate hydriodide micronized to a particle size of 0-5 microns. It can also include various alternative excipients. In particular those shown in Table II: Table II: Example Constituents Constituent Examples Active ingredient Penethamate hydriodide nous vehicle/s A biocompatible oil of vegetable, animal or synthetic origin. Preferably selected from oils such as canola oil, 205366NZC_COMPLETESPEC2_20131217_1337_JWP FEE CODE – 1050 t oil, corn oil, cottonseed oil, olive oil, peanut oil, palm oil, sesame oil, soybean oil, safflower oil, sunflower oil. Triglycerides, which are long chain fatty acid esters of glycerol, or mixtures of triglycerides and fatty acids (such as MIGLYOL®). Trihydroxy, dihydroxy, monohydroxy or even polyhydroxy compounds may be substituted for the glycerol.

Organic solvent vehicle/s DGMEE, Solketal, Propylene Glycol Oil miscible c vehicle/s Caprylic/Capric Triglycerides (e.g. CRODOMOL® GTCC, Croda), Isopropyl myristate, alcohol, glycerin, polyethylene glycol and polypropylene glycol tant/s Lecithin, Sorbitan esters, polyoxyethylated sorbitan esters, polyethylene glycol te Buffer/s Such as citrate and phosphate buffering agents Suspending agent/s Such as gums (e.g., acacia, carrageenan, tes and tragacanth), cellulosics (e.g., Methylcellulose, Hydroxyethylcellulose, Carboxymethylcellulose, Sodium Carboxymethylcellulose, Microcrystalline cellulose), and clays (e.g., bentonite and colloidal magnesium aluminum) g agent/s Lecithin, Anionic (e.g., docusate sodium and sodium lauryl e) and nonionic (polysorbates, polyoxamers, octoxynol-9) Flocculating agent/s Such as Sorbitan , yethylated sorbitan esters Thickener/s Such as gelatin, x, hydrogenated oils, 12- hydroxystearin, aluminium stearate, lactose, natural gums and cellulose derivatives (such as those listed above as suspending agents) Surface modifier/s Such as gelatin, casein, lecithin, gum acacia, cholesterol, tragacanth, c acid, benzalkonium chloride, calcium stearate, glyceryl monostearate, cetostearyl alcohol, 205366NZC_COMPLETESPEC2_20131217_1337_JWP FEE CODE – 1050 cetomacrogol emulsifying wax, sorbitan esters, polyoxyethylene alkyl ethers, polyoxyethylene castor oil tives, polyoxyethylene sorbitan fatty acid esters, polyethylene glycols, polyoxyethylene tes, colloidal silicon dioxide, phosphates, sodium dodecylsulfate, carboxymethylcellulose calcium, carboxymethylcellulose sodium, methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxypropylmethycellulose phthalate, noncrystalline cellulose, magnesium aluminum te, triethanolamine, polyvinyl alcohol, and polyvinylpyrrolidone Moisture ger/s Such as cross-linked polyvinylpyrolidone (CL-PVP or crospovidone USP/NF (e.g. POLYPLASDONE® XL and XL- , Ashland), celluloses and cellulosic materials, such as purified cellulose, microcrystalline cellulose, methylcellulose, carboxymethylcellulose and sodium carboxymethylcellulose, food grade sources of α- and ous cellulose (e.g., ®), and powdered cellulose, silica, tribasic m phosphate, sodium carboxymethylcellulose (sodium CMC), croscarmellose sodium (e.g., AC-DI-SOL®,FMC), and the like.

Osmotic agents Such as sodium chloride, sodium sulfate, dextrose, ol and glycerol Local Anaesthetic/s Lidocaine, Bupivacaine, Tetracaine, Procaine, Mepivacaine Preservative/s Such as methyl and propyl paraben, benzyl alcohol, chlorobutanol and thimerosal may be added Antioxidant/s Such as Ascorbic acid derivatives (e.g. ascorbic acid, rbic acid, sodium ascorbate), Thiol derivatives (e.g. thioglycerol, cysteine, acetylcysteine, cystine, 205366NZC_COMPLETESPEC2_20131217_1337_JWP FEE CODE – 1050 dithioerythreitol, dithiothreitol, glutathione), Tocopherols, Butylated hydroxyanisole(BHA), Butylated hydroxytoluene (BHT), Sulfurous acid salts (e.g. sodium sulfate, sodium bisulfite, acetone sodium bisulfite, sodium metabisulfite, sodium sulfite, sodium formaldehyde ylate, and sodium lfate), Nordihydroguaiaretic acid The wetting or dispersing agent may be present in an amount of about 0.01% (w/v) to about 1% (w/v) based on the total volume of the formulation. More typically, the wetting or dispersing agent may be t in an amount of about 0.01% (w/v) to about 0.5% (w/v), about 0.01% (w/v) to about 0.1% (w/v), or about 0.05% (w/v) to about 0.2% (w/v). Preferably, the wetting or dispersing agent may be present in an amount of about 0.05% w/v. Advantageously, the wetting or dispersing agent may comprise in (such as PHOSPHOLIPON® 90H, Lipoid). In one embodiment, PHOSPHOLIPON® 90H may be present in an amount of about 0.01% to about 0.10% w/v, and even more advantageously, about 0.05% w/v.

Hydrophilic ds such as Lecithin coat hydrophobic drug particles (in this case the penethamate hydriodide) in one or more than one layer. This provides hydrophillicity to the drug particles and facilitate wetting. This aids deflocculation of the suspension because force of attraction between the particles is reduced.

In a particularly preferred embodiment the PHOSPHOLIPON®, along with Polyoxyethylated sorbitan ester (TWEEN®, Croda) , and Sodium Citrate are blended with the Penethamate hydriodide before oration into the liquid carrier solution. By such an inclusion at the API manufacturing site further processing at a formulation facility can be much fied.

The constituents of a preferred oily suspension ation are listed in Table III Table III: Constituents of Preferred Formulation Constituent Purpose Concentration Penethamate hydriodide Active ingredient 10-70% 205366NZC_COMPLETESPEC2_20131217_1337_JWP FEE CODE – 1050 Lecithin (e.g. Surfactant <1% PHOSPHOLIPON® E80) yethylated sorbitan tant 1% ester (e.g. TWEEN® 80) () or Sorbitan ester (SPAN®, Croda) Silicon dioxide (e.g. Thixotropic agents <1% AEROSIL® 200) Sodium Citrate Preservative 0-5% Citric acid Buffer 0-5% Propylene glycol Solvent 0-30% Methyl Paraben or benzyl Preservative 0-5% alcohol A Antioxidant 0-1% Caprylic/Capric Triglyceride Carrier 20-90% (e.g. MIGLYOL® 812 and/or 840) In this embodiment, the biocompatible oil vehicle comprises MIGLYOL® 812, a ic/Capric Triglyceride. An example of an alternative carrier is CRODAMOL® GTCC, supplied by Croda Health Care.

A further and more simple embodiment would include penethamate, lecithin, Polyoxyethylated sorbitan ester (TWEEN®) and Citric Acid.

The constituents of a preferred c solvent suspension formulation are listed in Table IV 205366NZC_COMPLETESPEC2_20131217_1337_JWP FEE CODE – 1050 Table IV: Constituents of Preferred Formulation Constituent Purpose Concentration Penethamate hydriodide Active ingredient 10-70% Lecithin (PHOSPHOLIPON® Surfactant <1% E80) Polyoxyethylated sorbitan Surfactant 1% ester (TWEEN® 80) or Sorbitan ester (SPAN®) Silicon dioxide (AEROSIL® Thixotropic agents <1% 200) Sodium Citrate Preservative 0-5% Citric acid Buffer 0-5% Methyl Paraben or benzyl Preservative 0-5% alcohol BHT/BHA Antioxidant 0-1% Solketal and/or DGMEE Carrier 20-90% Method of Manufacture: The sion of the present invention may be prepared by any method known in the art for the ation of injectable suspensions. All such methods involve the active ingredient being present in a le solid form and suspension f in a liquid vehicle. However, if the 205366NZC_COMPLETESPEC2_20131217_1337_JWP FEE CODE – 1050 formulation ns lecithin (such as PHOSPHOLIPON®), the lecithin may be added to the penethamate hydriodide as a dry powder or via a heating and cooling step.

A manufacturing facility suitable for producing sterile products must be used if one is making this composition as an injectable for commercial use. Also, all manufacturing equipment and packaging components should be sterilized when making the sion for administration by injection.

In the present invention, it is desirable to have as little water in the formulation as le. The ce of water may cause a ion in the shelf life of the formulation.

A number of alternative processing methods can be used to prepare the formulation. For example: Method 1 1. Blend penethamate hydriodide, Lecithin (PHOSPHOLIPON®), Sodium citrate acid, Polyoxyethylated sorbitan ester (TWEEN®) or Sorbitan ester (SPAN®) in the sterile dry powder 2. Place a volume of the carrier oil or solvent into a vessel 3. Add the penethamate hydriodide blend 4. Mix well and homogenize . Fill into sterile bottles. 6. Cap seal and label. 7. Optionally sterilise by gamma irradiation Method 2: 1. Mix all excipients in the carrier oil or solvent, use heat if . 2. Sterile filter into sterile vessel. 3. Allow to cool 4. Add sterile Penethamate Hydriodide, mix homogenize and fill into sterile bottles. Cap seal and label.

. Optionally sterilize by gamma irradiation.

Method 3: 205366NZC_COMPLETESPEC2_20131217_1337_JWP FEE CODE – 1050 1. Place a volume of the oil into a vessel 2. Heat above 100°C 3. Add the lecithin (PHOSPHOLIPON®) and stirred until dissolved. 4. Allow to cool . Add and mix the Polyoxyethylated sorbitan ester (TWEEN®) or an ester (SPAN®) 6. Add the penethamate hydriodide 7. Mix well and homogenize 8. Fill into sterile bottles. 9. Cap seal and label.

. Optionally sterilize by gamma irradiation Formulation development Formulation pment for penethamate suspensions An attempt was made to formulate penethamate hydriodide as a suspension in oily solvents. Trial batches were made using the following oils: medium chained triglyceride (caprylic/capric cerides, CRODAMOL® GTCC), MIGLYOL® 840 (propylene glycol dicaprylate / dicaprate), glycerol triacetate, ethyl oleate and benzyl benzoate. Methyl paraben was added as a preservative. tant(s) such as egg lecithin, polyoxyethylated sorbitan ester (TWEEN® 80) and/or sorbitan ester (SPAN® 80) were/was added as dispersant(s). Benzyl alcohol or propylene glycol was included in some of the batches as a co-solvent. About 16.7 g of amate was added to 50 ml oily e, and homogenized at 5000 rpm for 10 min.

Table V: Penethamate suspensions in oils AL63- AL63- AL63- AL63- AL63- AL63- Materials %w/v 06 07 08 09 10 11 SPAN® 80 0.5 √ √ TWEEN® 80 0.5 √ √ Egg lecithin 0.5 √ √ √ √ Methyl paraben 0.15 √ √ √ √ √ √ 205366NZC_COMPLETESPEC2_20131217_1337_JWP FEE CODE – 1050 Benzyl alcohol 1 Propylene glycol 1 BHT 0.1 AEROSIL® 200 0.5 Medium chain ceride qs √ √ √ MIGLYOL® 840 qs √ √ √ DISCOLORATION? NO NO NO NO NO NO 205366NZC_COMPLETESPEC2_20131217_1337_JWP FEE CODE – 1050 Table V: (continued) AL63- AL63- AL63- AL63- AL63- als %w/v 12 13 14 15 16 AL63-17 SPAN® 80 0.5 √ √ TWEEN® 80 0.5 √ √ √ √ Egg lecithin 0.5 √ √ √ √ √ √ Methyl paraben 0.15 √ √ √ √ √ √ Benzyl alcohol 1 √ √ √ Propylene glycol 1 √ √ √ BHT 0.1 AEROSIL® 200 0.5 √ √ Medium chain triglyceride qs √ √ √ √ √ √ MIGLYOL® 840 qs DISCOLORATION? NO NO NO NO NO NO Table V: (continued) AL63-26 AL63-27 AL63- AL63-29 AL63-32 als %w/v 28 SPAN® 80 0.5 √ √ √ √ √ TWEEN® 80 0.5 Egg lecithin 0.5 √ √ √ Methyl paraben 0.15 √ √ √ √ √ Benzyl alcohol 1 Propylene glycol 1 205366NZC_COMPLETESPEC2_20131217_1337_JWP FEE CODE – 1050 BHT 0.1 AEROSIL® 200 0.5 Medium chain triglyceride qs L® 840 qs Glycerol triacetate qs √ √ Ethyl oleate qs √ √ Benzyl bezoate qs √ DISCOLORATION? NO NO Table V: (continued) Materials %w/v AL63-33 AL63-34 AL63-35 AL63-36 SPAN® 80 0.5 √ TWEEN® 80 0.5 √ √ √ Egg lecithin 0.5 √ √ √ Methyl paraben 0.15 √ √ √ √ Benzyl alcohol 1 Propylene glycol 1 BHT 0.1 AEROSIL® 200 0.5 √ √ √ Medium chain ceride qs √ √ MIGLYOL® 840 qs √ Glycerol triacetate qs Ethyl oleate qs √ Benzyl bezoate qs DISCOLORATION? NO NO NO 205366NZC_COMPLETESPEC2_20131217_1337_JWP FEE CODE – 1050 It was noticed that medium chain triglyceride, Propylene glycol dicaprylate/dicaprate (MIGLYOL® 840) and glycerol triacetate may be more le oils for amate oily suspensions, as the corresponding batches showed no significant discolouration when ed.

TABLE VI: RESUSPENSION AL63-06 AL63-07 AL63-08 AL63-09 AL63-10 AL63-11 Separation after centrifuging at 17 24 11 27 14 28 1000rpm for 10min (mm) Separation after centrifuging at 22 23 24 26 24 27 1000rpm for 20min (mm) none none most most some some Re-suspension (24 suspende suspende suspende suspende de suspende rpm for 1min) d d d d d d none none most most some some Re-suspension (24 suspende suspende suspende suspende suspende suspende rpm for 4min) d d d d d d Sedimentation rate 0.100 0.124 0.115 0.183 0.180 0.187 (ml/hour) 205366NZC_COMPLETESPEC2_20131217_1337_JWP FEE CODE – 1050 l—TABLE Vl: contd.

AL63-12 3 TAL53—14—' AL63—15J AL63—16_' AL63—17 l ‘7 tion after —I T T centrifuging at 14 15 14 24 14 20 1000rpm for 10min (mm) _| J Separation after centrifuging at 22 -25 24 28 22 24 1000rpm for 20min (mm) I— i i 4 most some some some some 4 some Re—suspension (24 suspende suspende suspende de suspende suspende rpm for 1min) d cl d d i cl d |_ J— most —I some some some some '— some Re-suspension (24 suspende suspende suspende suspende suspende suspende rpm for 4min) d d d d d d ntation rate—l T —1 +— 0.098 0.103 0.090 0.095 0.027 0.989 (ml/hour) All batches were observed for discolouration. Only a few batches showed no sign of discolouration after one month at room ature, these were AL63-06, AL63—07, AL63—10, AL63-11, AL63-29 and AL63—33. This demonstrates that the combination of SPAN® 80/egg lecithin, TWEEN® 80/ egg lecithin, TWEEN® 80/egg lecithin/benzyl alcohol, and TWEEN® 80/egg lecithin/propylene glycol may interact with formulation ingredients and result in discolouration.

The batches without discolouration were subjected to manual re-suspension studies.

Further, butylated hydroxytoluene (BHT) was introduced into the formulations as an antioxidant, as shown in Table Vll. None of the batches containing BHT showed discolouration, indicating that BHT may be efficient in avoiding discolouration.

Table VII: Penethamate suspensions in oils containing BHT AL63— AL63- AL63- AL63— AL63— Materials %w/v 37 47 48 49 50 SPAN® 80 0.5 V V T V TWEEN® 80 0.5 V V Egg lecithin 0.5 V J— ._l_ __I Methyl paraben 0.15 V _l— V V V V BHT 0.1—1 v v } v v v AEROSlL® 200 0.5 + Medium chain ceride qs V MIGLYOL® 840 qs V V ol triacetate qs V V Stability studies in which the formulations were ted to ed temperatures demonstrated that the oily suspensions were highly stable.

Formulation development for amate suspension in organic solvents Following indications of success with oily vehicles it was speculated that it may be possible to use organic solvents as potential vehicles for a penethamate suspension. Solubility of penethamate was estimated at the concentrations of 0.2% w/w and 1.0% w/w, in the ing solvents: glycerine, Solketal, polyethylene glycol 200 (PEG 200), diethylene glycol butyl ether (DGBE), 205366NZC_COMPLETESPEC2_20131217_1337_JWP FEE CODE — 1050 propylene glycol (PG), glycofural, diethylene glycol monomethyl ether (DGME), diethylene glycol methyl ethyl ether (DGMEE), dimethyl isosorbide (DMI), 2-pyrrolidone ol), N-methyl pyrrolidone (NMP), dimethyl acetamide (DMA), glycerol formal (GF), benzyl alcohol (BA), ethyl lactate and dimethyl sulfoxide (DMSO). The resulting solutions/dispersions were observed for discolouration, which is an indication of instability in such solvents.

The ts in which 0.2% w/w and 1.0% w/w penethamate showed no discolouration and minimal solubility were selected as the solvent ates for the formulation development for penethamate suspensions in organic vehicles. The selected solvents were glycerine, Solketal, propylene glycol, glycerol formal and DGMEE.

The ing ations (as shown in Table VIII) were ed for the development of penethamate suspensions in organic vehicles, because they showed minimum physical changes in earlier work. Each of them was divided into two portions and stored at 2-8°C and 55°C for 2 weeks, and then ed for penethamate content (as shown in Table IX). The results demonstrate that propylene glycol, Solketal and DGMEE were promising vehicles for penethamate suspensions, compared to the other tested organic vehicles.

Table VIII: amate suspensions in organic vehicles AL63- AL63- AL63- AL63- AL63- AL63- AL63- Materials 43 44 45 46 51 52 53 BHT - - - 0.01g - - - GF - - - - - - - Glycerine - 10g 5g 5g - - - PG 10g - 5g 5g - - 10g Solketal - - - - 10g - - DGMEE - - - - - 10g - Penethamate 3.3g 3.3g 3.3g 3.3g 3.3g 3.3g 3.3g 205366NZC_COMPLETESPEC2_20131217_1337_JWP FEE CODE – 1050 Table IX: amate assay in penethamate suspensions in organic es BN Solvent % amate %BHT Recovery (%) AL63- 43 PG 3.3g in 10ml - 61.65 AL63- 44 Glycerin 3.3g in 10ml - 81.86 AL63- 45 PG/Glycerin 3.3g in 10ml - 62.02 AL63- 46 PG/Glycerin 3.3g in 10ml 0.1 33.45 AL63- 51 Solketal 3.3g in 10ml - 99.81 AL63- 52 DGMEE 3.3g in 10ml - 96.84 AL63- 53 PG 3.3g in 10ml - 66.03 To confirm that propylene glycol, Solketal and DGMEE were suitable solvents for penethamate suspensions, the following batches were prepared and subjected to further stress studies (as shown in Table X). Corresponding batches containing BHT were also made and tested for comparison. The results (as shown in Table XI) were very comparable to those shown in table IX.

Solketal and DGMEE are the most suitable organic vehicles for penethamate suspensions, with about 100% and 97% recovery of penethamate respectively. Moreover, the addition of BHT did not seem to enhance the stability of penethamate suspensions in the organic vehicles as they did in the oil-based suspensions.

Table X: amate suspensions in propylene glycol, Solketal and DGMEE Materials AL63- AL63- AL63- AL63- AL63- AL63- 205366NZC_COMPLETESPEC2_20131217_1337_JWP FEE CODE – 1050 54 55 56 57 58 59 BHT - - - 0.1 0.1 0.1 Solketal 10g - - 10g - - DGMEE - 10g - - 10g - PG - - 10g - - 10g Penethamate 3.3g 3.3g 3.3g 3.3g 3.3g 3.3g Table XI: Penethamate assay in penethamate suspensions in propylene glycol, Solketal and DGMEE BN Solvent % amate %BHT Recovery (%) AL63- 54 Solketal 3.3g in 10ml - 100.79 AL63- 55 DGMEE 3.3g in 10ml - 96.83 AL63- 56 PG 3.3g in 10ml - 65.33 AL63- 57 Solketal 3.3g in 10ml 0.1 100.44 AL63- 58 DGMEE 3.3g in 10ml 0.1 95.92 AL63- 59 PG 3.3g in 10ml 0.1 61.70 Further, penethamate suspensions in the combination of Solketal and DGMEE were formulated (as shown in Table XII) and subjected to stress studies. The results are shown in Table XIII.

Table XII: Penethamate suspensions in the combination of Solketal and DGMEE 205366NZC_COMPLETESPEC2_20131217_1337_JWP FEE CODE – 1050 Materials AL63-60 AL63-61 BHT - 0.1 Solketal 5g 5g DGMEE 5g 5g Penethamate 3.3g 3.3g Table XIII: Penethamate assay in organic es suspensions in the ation of Solketal and DGMEE BN Solvent % Penethamate %BHT Recovery (%) AL63- Solketal/DGMEE 3.3g in 10ml - 96.58 AL63- Solketal/DGMEE 3.3g in 10ml 0.1 96.53 The sions produced by the above methods demonstrate all the characteristics required for a suitable ready to use penethamate hydriodide ation: - Easy to resuspend without the need for vigorous shaking - Good ility and syringeability - Uniform appearance - Physical, Chemical and iological stability - Easy to process and sterilise Injection site tolerance studies were undertaken in which animals were treated with the various embodiments of the invention. In all cases the formulations were well tolerated with no adverse reactions.

Suspension formulations of Penethamate with other actives.

Surprisingly and quite unexpectedly it has also proven possible to orate an analgesic agent in the formulation including the organic solvents. This has been achieved by successfully dissolving 205366NZC_COMPLETESPEC2_20131217_1337_JWP FEE CODE – 1050 the agent in the solvent blend while the penethamate remains suspended. It is anticipated that other analgesic agents and other soluble actives may also be used. To prepare the formulation the analgesic agent is firstly dissolved in the solvent blend. Once this is achieved the penethamate is added.

Examples of such formulations are as s: Penethamate/Ketoprofen Formulation Materials Concentration Penethamate 33% ofen 10% BHT 0.1% DGMEE 25% Solketal To vol Penethamate/Ketoprofen Formulation Materials Concentration Penethamate 33% Ketoprofen 10% BHT 0.1% Solketal To vol Such a product has significant advantages in that it enables co-administration of a bacterial agent and analgesic to s that would benefit from such a treatment. Given that the bacterial agent and analgesic agent typically require quite different formulation ions the invention of a system able to incorporate both agents is a useful milestone. It is anticipated that other sic agents such as in, tolfenamic acid, carprofen, meloxicam and metamizole might also be used. 205366NZC_COMPLETESPEC2_20131217_1337_JWP FEE CODE – 1050 Advantages: The invention provides a ready to use suspension formulation of penethamate.

The ready to use suspension formulation is suitable for intramuscular injection in domestic animals; in particular .

It needs only shaking of the vial (or other container) to achieve adequate re-suspension and is thus easier and quicker to use on the farm then previous injectable forms of penethamate.

Prior References: All references, including any s or patent applications cited in this specification are hereby incorporated by reference. No admission is made that any reference constitutes prior art. The discussion of the nces states what their authors , and the applicants e the right to challenge the accuracy and pertinency of the cited documents. It will be y understood that, although a number of prior art publications may be referred to herein; this reference does not constitute an admission that any of these documents form part of the common general knowledge in the art, in New Zealand or in any other country.

Definitions: It is acknowledged that the term ‘comprise’ may, under varying jurisdictions, be attributed with either an exclusive or an inclusive meaning. For the purpose of this ication, and unless otherwise noted, the term ‘comprise’ shall have an ive meaning - i.e. that it will be taken to mean an inclusion of not only the listed components it directly references, but also other nonspecified components or elements. This rationale will also be used when the term ‘comprised’ or 'comprising' is used in relation to one or more steps in a method or process. 205366NZC_COMPLETESPEC2_20131217_1337_JWP FEE CODE – 1050 The phrase “substantially water free” used in connection with the formulations of this invention is to be understand that water is not an intentional ingredient of the formulation and that whilst water should not be present in the formulation that if some water is detected in the formulation that an amount of less than 1% of the formulation will be within the meaning of this phrase.

MIGLYOL® is a trademark for various distillation fractions of coconut oil, typically comprising a mixture of triglycerides of C8 and triglycerides of C10 fatty acids.

“Ready to use” in on to the formulation means that no other additives or reconstitution steps are needed – just that the formulation can be shaken or agitated before being administered. ions: It will of course be realised that while the foregoing has been given by way of rative example of this invention, all such and other modifications and variations thereto as would be apparent to persons skilled in the art are deemed to fall within the broad scope and ambit of this invention as is hereinbefore bed. 205366NZC_COMPLETESPEC2_20131217_1337_JWP FEE CODE – 1050

Claims (12)

1. An injectable veterinary suspension formulation comprising penethamate or a salt f and a substantially water free carrier comprising diethylene glycol monoethyl ether and/or solketal.

2. An injectable veterinary suspension formulation as claimed in claim 1 n the amate is present as penethamate hydriodide, and the formulation includes one or more pharmaceutically acceptable excipients suitable for intramuscular injection in domestic animals; in particular cattle.

3. An injectable veterinary suspension formulation as claimed in claim 1 or 2 wherein the r includes a biocompatible oil selected from the group: canola oil, coconut oil, corn oil, cottonseed oil, olive oil, peanut oil, palm oil, sesame oil, soybean oil, safflower oil, sunflower oil, cerides and mixtures of triglycerides and fatty acids.

4. An injectable veterinary suspension formulation as d in claim 3, wherein the mixture of triglyceride and fatty acids is selected from one of the MIGLYOL® mixtures.

5. An injectable veterinary suspension formulation as claimed in claim 3, wherein the triglycerides are selected from long chain fatty acid esters of (a) glycerol or (b) trihydroxy, dihydroxy, monohydroxy or polyhydroxy compounds.

6. An injectable veterinary suspension ation as claimed in any preceding claim which also es a moisture scavenger.

7. An injectable veterinary suspension formulation as claimed in claim 7, wherein the moisture scavenger is selected from cross‐linked polyvinylpyrolidone, celluloses and cellulosic als, food grade sources of α‐ and amorphous cellulose , powdered cellulose, silica, tribasic calcium phosphate, sodium carboxymethylcellulose, and croscarmellose sodium.

8. An injectable nary suspension ation as d in claim 9, wherein the moisture scavenger is selected from ed cellulose, microcrystalline ose, methylcellulose, carboxymethylcellulose and sodium carboxymethylcellulose.

9. An injectable veterinary suspension formulation as claimed in any preceding claim which also includes an analgesic.

10. An injectable veterinary suspension formulation as claimed in claim 9 wherein the analgesic is ketoprofen.

11. An injectable veterinary formulation according to claim 1, wherein the r consists at least predominantly of diethylene glycol monoethyl ether.

12. An injectable veterinary formulation according to claim 1, wherein the carrier consists at least predominantly of solketal.